In the future, in the city of Metropolis, wealthy industrialists and business magnates and their top employees reign from high-rise towers, while underground-dwelling workers toil to operate the great machines that power the city. Joh Fredersen is the city's master. His son Freder idles away his time at sports and in a pleasure garden, but is interrupted by the arrival of a young woman named Maria, who has brought a group of workers' children to witness the lifestyle of their rich "brothers". Maria and the children are ushered away, but Freder, fascinated, goes to the lower levels to find her. On the machine levels he witnesses the explosion of a huge machine that kills and injures numerous workers. Freder has a hallucination that the machine is Moloch and the workers are being fed to it. When the hallucination ends and he sees the dead workers being carried away on stretchers, he hurries to tell his father about the accident; Fredersen asks his assistant, Josaphat, why he learned of the explosion from his son, and not from him.